linux/drivers/iio/adc/mp2629_adc.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * MP2629 Driver for ADC
   4 *
   5 * Copyright 2020 Monolithic Power Systems, Inc
   6 *
   7 * Author: Saravanan Sekar <sravanhome@gmail.com>
   8 */
   9
  10#include <linux/iio/driver.h>
  11#include <linux/iio/iio.h>
  12#include <linux/iio/machine.h>
  13#include <linux/mfd/mp2629.h>
  14#include <linux/module.h>
  15#include <linux/mutex.h>
  16#include <linux/platform_device.h>
  17#include <linux/regmap.h>
  18
  19#define MP2629_REG_ADC_CTRL             0x03
  20#define MP2629_REG_BATT_VOLT            0x0e
  21#define MP2629_REG_SYSTEM_VOLT          0x0f
  22#define MP2629_REG_INPUT_VOLT           0x11
  23#define MP2629_REG_BATT_CURRENT         0x12
  24#define MP2629_REG_INPUT_CURRENT        0x13
  25
  26#define MP2629_ADC_START                BIT(7)
  27#define MP2629_ADC_CONTINUOUS           BIT(6)
  28
  29#define MP2629_MAP(_mp, _mpc) IIO_MAP(#_mp, "mp2629_charger", "mp2629-"_mpc)
  30
  31#define MP2629_ADC_CHAN(_ch, _type) {                           \
  32        .type = _type,                                          \
  33        .indexed = 1,                                           \
  34        .datasheet_name = #_ch,                                 \
  35        .channel = MP2629_ ## _ch,                              \
  36        .address = MP2629_REG_ ## _ch,                          \
  37        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
  38        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
  39}
  40
  41struct mp2629_adc {
  42        struct regmap *regmap;
  43        struct device *dev;
  44};
  45
  46static struct iio_chan_spec mp2629_channels[] = {
  47        MP2629_ADC_CHAN(BATT_VOLT, IIO_VOLTAGE),
  48        MP2629_ADC_CHAN(SYSTEM_VOLT, IIO_VOLTAGE),
  49        MP2629_ADC_CHAN(INPUT_VOLT, IIO_VOLTAGE),
  50        MP2629_ADC_CHAN(BATT_CURRENT, IIO_CURRENT),
  51        MP2629_ADC_CHAN(INPUT_CURRENT, IIO_CURRENT)
  52};
  53
  54static struct iio_map mp2629_adc_maps[] = {
  55        MP2629_MAP(BATT_VOLT, "batt-volt"),
  56        MP2629_MAP(SYSTEM_VOLT, "system-volt"),
  57        MP2629_MAP(INPUT_VOLT, "input-volt"),
  58        MP2629_MAP(BATT_CURRENT, "batt-current"),
  59        MP2629_MAP(INPUT_CURRENT, "input-current")
  60};
  61
  62static int mp2629_read_raw(struct iio_dev *indio_dev,
  63                        struct iio_chan_spec const *chan,
  64                        int *val, int *val2, long mask)
  65{
  66        struct mp2629_adc *info = iio_priv(indio_dev);
  67        unsigned int rval;
  68        int ret;
  69
  70        switch (mask) {
  71        case IIO_CHAN_INFO_RAW:
  72                ret = regmap_read(info->regmap, chan->address, &rval);
  73                if (ret)
  74                        return ret;
  75
  76                if (chan->address == MP2629_INPUT_VOLT)
  77                        rval &= GENMASK(6, 0);
  78                *val = rval;
  79                return IIO_VAL_INT;
  80
  81        case IIO_CHAN_INFO_SCALE:
  82                switch (chan->channel) {
  83                case MP2629_BATT_VOLT:
  84                case MP2629_SYSTEM_VOLT:
  85                        *val = 20;
  86                        return IIO_VAL_INT;
  87
  88                case MP2629_INPUT_VOLT:
  89                        *val = 60;
  90                        return IIO_VAL_INT;
  91
  92                case MP2629_BATT_CURRENT:
  93                        *val = 175;
  94                        *val2 = 10;
  95                        return IIO_VAL_FRACTIONAL;
  96
  97                case MP2629_INPUT_CURRENT:
  98                        *val = 133;
  99                        *val2 = 10;
 100                        return IIO_VAL_FRACTIONAL;
 101
 102                default:
 103                        return -EINVAL;
 104                }
 105
 106        default:
 107                return -EINVAL;
 108        }
 109}
 110
 111static const struct iio_info mp2629_adc_info = {
 112        .read_raw = &mp2629_read_raw,
 113};
 114
 115static int mp2629_adc_probe(struct platform_device *pdev)
 116{
 117        struct device *dev = &pdev->dev;
 118        struct mp2629_data *ddata = dev_get_drvdata(dev->parent);
 119        struct mp2629_adc *info;
 120        struct iio_dev *indio_dev;
 121        int ret;
 122
 123        indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
 124        if (!indio_dev)
 125                return -ENOMEM;
 126
 127        info = iio_priv(indio_dev);
 128        info->regmap = ddata->regmap;
 129        info->dev = dev;
 130        platform_set_drvdata(pdev, indio_dev);
 131
 132        ret = regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
 133                                MP2629_ADC_START | MP2629_ADC_CONTINUOUS,
 134                                MP2629_ADC_START | MP2629_ADC_CONTINUOUS);
 135        if (ret) {
 136                dev_err(dev, "adc enable fail: %d\n", ret);
 137                return ret;
 138        }
 139
 140        ret = iio_map_array_register(indio_dev, mp2629_adc_maps);
 141        if (ret) {
 142                dev_err(dev, "IIO maps register fail: %d\n", ret);
 143                goto fail_disable;
 144        }
 145
 146        indio_dev->name = "mp2629-adc";
 147        indio_dev->dev.parent = dev;
 148        indio_dev->channels = mp2629_channels;
 149        indio_dev->num_channels = ARRAY_SIZE(mp2629_channels);
 150        indio_dev->modes = INDIO_DIRECT_MODE;
 151        indio_dev->info = &mp2629_adc_info;
 152
 153        ret = iio_device_register(indio_dev);
 154        if (ret) {
 155                dev_err(dev, "IIO device register fail: %d\n", ret);
 156                goto fail_map_unregister;
 157        }
 158
 159        return 0;
 160
 161fail_map_unregister:
 162        iio_map_array_unregister(indio_dev);
 163
 164fail_disable:
 165        regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
 166                                         MP2629_ADC_CONTINUOUS, 0);
 167        regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
 168                                         MP2629_ADC_START, 0);
 169
 170        return ret;
 171}
 172
 173static int mp2629_adc_remove(struct platform_device *pdev)
 174{
 175        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 176        struct mp2629_adc *info = iio_priv(indio_dev);
 177
 178        iio_device_unregister(indio_dev);
 179
 180        iio_map_array_unregister(indio_dev);
 181
 182        regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
 183                                         MP2629_ADC_CONTINUOUS, 0);
 184        regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
 185                                         MP2629_ADC_START, 0);
 186
 187        return 0;
 188}
 189
 190static const struct of_device_id mp2629_adc_of_match[] = {
 191        { .compatible = "mps,mp2629_adc"},
 192        {}
 193};
 194MODULE_DEVICE_TABLE(of, mp2629_adc_of_match);
 195
 196static struct platform_driver mp2629_adc_driver = {
 197        .driver = {
 198                .name = "mp2629_adc",
 199                .of_match_table = mp2629_adc_of_match,
 200        },
 201        .probe          = mp2629_adc_probe,
 202        .remove         = mp2629_adc_remove,
 203};
 204module_platform_driver(mp2629_adc_driver);
 205
 206MODULE_AUTHOR("Saravanan Sekar <sravanhome@gmail.com>");
 207MODULE_DESCRIPTION("MP2629 ADC driver");
 208MODULE_LICENSE("GPL");
 209